Packaging apparatus

ABSTRACT

Apparatus and method of packaging liquids wherein an elongated plastic envelope, sealed at one end, is filled with liquid under predetermined static pressure and a selected liquid-filled portion thereof is then heat-sealed and severed from the remainder of the envelope; the liquid being isolated from the heat-sealing and severing zone during such operations to prevent heating the liquid to boiling or gasifying temperatures.

United States Patent 11 1 Watkins 51 Apr. 1, 1975 1 1 PACKAGINGAPPARATUS 2.916.864 12/1959 Meissner 53/180 2.936.816 5/1960 Lav.53/181) X 175] inventor: Luclus waikms, Hamand' 3,164,936 1/1965toiiier 53/180 73 Assignee; per-mick, Inc" Naples m 3.282.020 11/1966Smith 53/180 3,611,657 10/1971 Inoue et al 53/180 X [22] Filed: Oct. 23,1973 [21] Appl. No.: 408,811 Primary Examiner-Robert L. Spruill RelatedU S Applicaflon Data Attorney, Agent, or Firm-Michael, Best & FriedrichI62] Division of Scr. No. 169,439. Aug. 5, 1971. Pat. No.

3.785.556. [5 7] ABSTRACT [52] U S Cl 53/182 Apparatus and method ofpackaging liquids wherein [5]] 9/12 an elongated plastic envelope,sealed at one end, is {58] i M 182 R filled with liquid underpredetermined static pressure 55/182 and a selected liquid-filledportion thereof is then heat-sealed and severed from the remainder ofthe en- {fil References and velope; the liquid being isolated from theheat-sealing and severing zone during such operations to prevent UNITEDSTATES PATENTS heating the liquid to boiling or gasifying temperatures.2.113.658 4/1938 Lukso 53/180 2.828.591 4/1958 Vundcn Bossche 53/180 X 3Claims, 9 Drawing Figures |r7 a i I 1 a 11 8473/6 55572 92 A g 1 5 1 130131 V I I 50 11; m 132) I #3 112 m r 1 -121Ji 35 in. 9

2 ye i APPARATUS This is a division of application Ser. No. 169.439.filed Aug. 5. 1971 now U.S. Pat. No. 3.785.556.

This invention relates generally to packaging. and more particularly. isdirected to improved means and method for encapsulating liquids within abeat-sealed plastic package to produce an improved product. particularlyuseful in disseminating vaporizablc liquids.

Various products for purifying. odorizing or deodorizing the atmosphereor for destroying or repelling insects are currently packaged inhermetically-sealed containers. Commonly used containers are eitherboxes. bottles. destructible plastic film enclosures or the like fromwhich the products. usually in solid or paste form. are removed for useso that the active components thereof may sublimatc or vaporize into theatmosphere.

it has been recognized for some time that such a program of diffusingmaterials of this nature is inefficient and ineffective. particularlyover extended periods of time, inasmuch as the relatively high degree ofeffectiveness thereof. experienced upon first exposing the same to theatmosphere. rapidly diminishes after a relatively short time due to theinability to regulate the rate of dispersion sublimation orvaporization. Attempts have been made to diffuse such materials withcontrolled rates of vaporization or sublimination. Generally speaking.howe\er. such efforts to date. particularly when dealing with solidmaterials. have been less than totally effective. in certain otherinstances. particularly with deodorants. release of liquid deodorizersthrough capillary wicking systems have proven somewhat more effectiveand acceptable in controlling the rate ofdisseminating the ingredientsto the atmosphere. Yet. these systems too are incapable of sustainingconstant rates of dispersion over extended periods.

It is known that liquid odorants. deodorants. repellents andinsecticides. particularly in highly concentrated forms. are highlyeffective for their intended purposes. However. to date. there has beenan absence of a simple. economical and efficient system for releasingthe active ingredients of odori7ers. deodorizers. repellents.insecticides and the like over extended periods of time so as to benefitfrom the capabilities of concentrated forms thereof. Foremost in theproblems confronting the utilization ofsuch liquids is the problem ofdiffusing or releasing the same to the atmosphere at a predeterminedrate so that the active substances thereof produce their desired effectsover extended time intervals. 'lypifying past efforts to overcome thisproblem is the invention described in U.S. Pat. No. 2.979.268 issuedApr. 1 l, l96l. or U.S. Pat. No. 3.216.882 issued Nov. 9. I965.

In brief. the present invention is directed to improvements in processs.apparatus and product whereby concentrated liquid odori7ers.deodorizers. insecticides. repellents and the like may be released tothe atmosphere at substantially constant rates for extended timeintervals. Essentially the basic scientific mechanism employed.according to this invention. for regulating the rate of release ofliquids is that of permeation by which is meant diffusion by absorptionnot to be confused with porosity or capillarity. This phenomenon ofpermeability. as herein employed. relates to utilization of plasticfilms and fluid compounds which are permeant thereto whereby the vaporrelease of ingredients at (ill the outer surface of the plasticmaterials after migration of the liquid ingredients therethrougheffectively produces an efficient and economical means for releasing theactive ingredients of the liquids to the atmosphere. ln simplifiedterms. a body of permeant liquid is encapsulated within a hermeticallysealed envelope of a homo-polymer plastic such as polyethylene orpolypropylene. When the packaged ingredients are exposed to atmosphere.the permeant liquid releases or vaporizes into the atmosphere at asubstantially constant rate dependent primarily on the migration abilityof the permeant through the plastic. This permeation rate generally isindependent of pressure so that regard less of whether the liquid ispressurized or dcpressurized within the container it progresses orpermeates through the plastic to produce a given quantity output perunit of area. Among other novel aspects of the present invention is theunique system of packaging such permeant liquids within the plasticcontainers, which preferably comprise an envelope of two superposedplastic layers. hermetically sealed around the borders or marginsthereof; the liquid filling the interior of the envelope anddisseminating across the interior walls of the package either bycapillary activity or direct liquid flow. Essentially. the interior ofthe envelope is free of any gaseous atmosphere which could affect theoutput ofthe permeant liquid. ln order to avoid boiling or gasifying theliquid permeant during the heatscaling open ation. which takes place attemperatures in excess of the normal boiling temperatures for theliquids. means are provided for effectively isolating or remoting theliquid ingredients from the mac to be heat sealed and- /or thermallysevered. Thus the liquids are effectively insulated from the undesirableeffects created by heat sealing and severing temperatures during thescaling process.

Among the objects of this invention is the provision of an improvedprocedure for encapsulating liquids in plastic containers. preferably inenvelope form.

Another object of this invention is to provide an im proved process forthermally sealing liquid-filled plastic containers without boiling orgasifying the liquid during the heat-sealing operation at temperaturesin excess of the boiling point for the liquid.

Still another object of this invention is to provide an improvedhermetically sealed package containing liquid permeant to the plasticwalls of the container.

A still further object ofthis invention is to provide an improvedpackaged product of liquid odorant sealed within a plastic containerpermeable to the odorant. whereby the latter is released from thecontainer at a substantially constant rate for an extended period oftime.

Still another object of this invention is to provide improved apparatusfor heat sealing a thermoplastic container about a body of liquid.

Having thus described this invention. the above and further objects.features and advantages thereof will be recognized by those familiarwith the art from the following detailed description of a preferredembodiment thereof. illustrated in the accompanying drawings.

hi the drawings:

FIG. I is a side elevational view setting forth the features ofapparatus for packaging liquids according to this invention:

FIG. 2 is a partial enlarged view in top plan with portions thereof insection taken substantially from vantage line 22 of HQ. 1 and looking inthe direction of the arrows thereon;

FIG. 3 is an enlarged cross sectional view taken substantially alongvantage line 3--3 of FIG. 1 and looking in the direction of the arrowsthereon;

HO. 4 is another enlarged cross sectional view taken substantially atvantage line 44 of FIG. 1. and looking in the direction of the arrowsthereon;

FIGS. 5, 6 and 7 are enlarged views in side elevation illustrating thesequential steps of heat sealing a plastic container about a body ofliquid according to this in vention'.

H6. 8 is an enlarged view in side elevation taken substantially fromvantage line 88 of FIG. 1 and looking in the direction of the arrowsthereon; and

FIG. 9 is a perspective view of a package produced according to thisinvention, showing the same broken open to illustrate capillarydistribution means employed therein.

Turning now to the particulars of the particular embodiment set forth inthe accompanying drawings for purposes of illustrating and describingthe present invention so as to enable those skilled in this art topractice the same, initial reference is made to FIG. I. As thereinshown, apparatus designated generally by numeral 10 is schematicallyrepresented for purposes of packaging liquid materials in accordancewith the present invention. As set out in this figure, a package tube orblank H is formed preferably from two rolls of tape l2, 12' ofpolyethylene film suitably supported by means not shown, but well withinthe normal capabilities of one skilled in this art. The width of thetape rolls is generally selected to be just slightly in excess of thedesired width for the end packaged product and the two rolls I2, 12' aremounted so as to oppose one another on opposite sides of a filler tube13. Thus the two layers of plastic 14 and 14 from the respective rollsl2, 12' thereof meet in opposing registration on opposite sides offiller tube l3. The plastic layers extend downwardly along the tube 13through a sealing and cutting assembly 15 to be described in greaterdetail presently. Assembly 15 functions both to heat-seal oppositelateral margins of the opposing plastic layers [4, l4 and to trim offexcess materials beyond the welded margins; the scrap being removed byperiodically actuated roller means 16 according to conventionalpractice.

The tubular package blank which exits from the seal ing and trimmingassembly [5 extends below the latter through a fluid level controlassembly I8, and into an under-disposed feeding assembly 19. Assembly 19serves to periodically grip the opposite lateral margins of the tubularpackage and pull the same downwardly through the sealing and trimmingassembly and level control assembly as will be described presently.Beneath the feeder assembly [9. the tubular package ll passes through anovel heat scaling and cut-off means 20 which serves to produceheat-sealed margins extending transversely between the sealed sidemargins of the tubular package 1]. Means 20 also optionally sev ers thetube 1] into selected lengths. in this manner, liquid-filled packagesare formed from the elongated tubular envelope H as will be amplifiedlater herein.

The lowermost end of the tubular package 11 abuts a verticallyadjustable stop gauge 21 which by its positioning regulated the verticaldimensions of the liquidfilled packages severed from the tube 1].

With particular reference now to FIGS. 1 and 2. the details of the tubesealing and trimmming assembly 15 will now be described. As best shownin these figures, assembly 15 comprises a supporting bracket 25 having acentral anvil portion 26 features by a concave face 27 against which oneof the plastic films 14'. for example, is shaped during the side marginscaling and trimming operations. Extending laterally outwardly ofopposite sides of the central anvil portion 26 are a pair of L- shapedarms 28 and 29. of which only 28 is shown in full plan in FIG. 2. Theparticulars of arm 28 and re lated elements will be described with theunderstanding that arm 29 and its arrangement with the mechanism areidentical thereto.

Pivotally connected to the outer end of arm 28 is a knife actuator 30mounted to pivot about pin means 31. Actuator 30 rocks about the pin 31in response to periodic energization of a solenoid means 32: beingjoined to the latter by connector rod 33 which passes through an opening34 in arm 28 and axially through a return spring means 35 mountedbetween arm 28 and the adjacent face of the actuator 30. A nut fastenermeans 36 is threaded over the outer end of the connector rod 33 on theopposite or outer side of actuator 30 to secure the latter to the rod 33and provide a means for adjusting the arcuate throw of the actuator asdeemed desirable. The non-pivotally supported or outer end of actuator30 is attached by bolt and nut fastener means 37 to a movable hotscaling knife 38 hav ing an electrical heater element 39 near the tipend thereof. Knife 38 opposes a stationary knife 40 adjustably mountedon one side of the central anvil portion 26. as by bolt fastener means41; the adjustability of knife 40 serving to accommodate varyingthicknesses for superposed plastic material of the layers 14, I4.

As with the movable sealing knife 38, the stationary knife 40 islikewise equipped with a heater element 42 near the outer end thereof toelevate the temperature thereof. In operation, the movable knife 38 isnormally at a temperature in excess of that required for sealing theplastic material while the stationary knife 40 is slightly below sealingtemperature. For polyethylene, typical temperature for knife 38 are inthe order of 320 F. and for the stationary knife 40 in the order of 280F. As best shown in FIG. 2, a second set of sealing knives 38' and 40'are provided on the opposite side of anvil portion 26 with the movementof the knife 38' being effected by a solenoid operated actuator of theorder above described, but not illustrated.

Supported opposite the central anvil portion 26 and located between thehot knives 38 and 38' is a movable anvil member 45 having an arcuatclyconcave face 46 which is adapted to receive and support the secondplastic film layer 14. Anvil member 45 is biased normally toward thestationary anvil portion 26 by spring means 47 affixed at one end to astationary support 48.

in operation. the assembly 15 has the two plastic lay ers 14. 14'gripped between the anvil portion 26 and member 45 with the filler tube13, preferably ofpliable material disposed therebetwcen. Periodicallythe two hot knife blades 38. 38' are moved toward abutting engagementwith the stationary knife blades 40, 40'. This occurs upon actuation ofsolenoid means 32 and its counterpart (not shown) associated with thesecond set of knife blades 38' and 40'. The hot knife blades pressthrough the two layers of plastic, melting the same until they abutagainst the stationary knife blades 40, 40'.

thereby effecting a thermal seal along the lateral margin of plasticlayers l4 and 14' held in assembly 15. When the opposing knife bladescontact one another they also sever the waste marginal portions 50. 50of the plastic layers from the central sealed envelope formed betweenthe margin seals. The scrap portions 50. 50' are pulled away by theroller assembly l6 across guide members 5]. 51' which are mountedalongside the stationary knife blade members 40, 40'.

In reponse to periodic actuation of the feeding assembly I). the tubularpackage member ll. laterally sealed by assembly 15. are periodicallyindexed or fed downwardly to bring unsealed portions of the plasticlayers [4. l4 into assembly where the sealing and trimming operationabove described are repeated. It will be appreciated that once thescaling and trimming operations take place. the heated knife elements38. 38' are withdrawn in response to deenergization of the actuatingsolenoid means therefor. such as solenoid 32 associated with theillustrated actuator 30. Energization of the solenoid means takes placeafter each downfeed operation of the tubular member 11 as will appear ingreater detail from the description which follows.

The tubular package 1] with its lateral margins now sealed, dependsdownwardly past the sealing and trimming assembly I5. as hereinabovedescribed, through the level control assembly I8 which will be bestunderstood by examination of FIGS. 1 and 3 of the drawings. From suchfigures. it will be recognized that a light source 55 is supported toone side of the tubular package member I I so as to shine toward aphotocell 56 lo cated on the opposite side of the package and disposedbetween the spaced arms of a generally U-shapcd guide member 57. Suchguide member is adjustably clamped to a support rod 58 dependingvertically between upper and lower arm portions 59 and 60 of a C-shapedsupporting bracket 6|. It will be noted that clamping connection ofmember 57 with support rod 58 is effected by bolt means 62 which permitadjustable positioning of the guide member 57 and the photocell 56vertically. Rod 58 is also threadingly fastened at its upper end to armportion 59 for adjustment purposes, although such adjustments arerelatively minor in normal operation.

With the abovedescribed arrangement for the assembly I8. it will beappreciated that when the tube member ll. having the lower end thereofsealed as illustrated in FIG. I. is filled with liquid up to the level63 indicated by dotted lines in FIG. I, the light energy from source 55is focused by the liquid between the opposing walls I4. I4 of the tubeII to energize photocell 56. Conversely. when the liquid level fallsbelow level 63, the light rays from source 55 fail to focus on cell 56and the latter is deencrgized. In its energized condition. cell 56.through suitable control circuitry, not shown. but well within the skillof those normally \ersed with this art. signals a liquid supply source(not shown) associated with filler tube 13 to shut off the supply ofadditional liquid to the interior of the tube member ll. Conversely whenthe cell 56 is deenergi'/ed. the liquid supply system is appropriatelyconditioned to supply liquid to filler tube 13. In this manner. thelevel of liquid within the tubular package member I I is maintainedsubstantially constant at level 63 so as to provide a predeterminedstatic head of liquid within the lower regions of the tubular packagemember 11.

It is to be noted from FIG. 3 in particular that the U- shaped member 57associated with the liquid level control assembly is provided with apair of guide elements 64. 64' having substantially V-shaped opposingfaces 65. 6S maintained in a spaced opposing relationship and betweenwhich tubular member II is trained. the apex of each face 65. 65'engaging one of the marginal seals of the package tube ll. The lateralspacing between the V-shaped guide surfaces is by design just slightlyless than the distance between the lateral margins of the unfilled tubeportion there-above (depicted in FIG. 2 showing the configuration of theunfilled tube member II in assembly 15 As a consequence. the V- shapedguide surfaces 65. 65' serve to how the tubular member outwardly betweenthe lateral sealed margins thereof. to bring about a generallypredetermined spac ing and cross section between the opposing walls l4,l4. This assists in filling the lower portions of the tubu lar memberwith a uniform volume of liquid determinative of the desired static headbut more importantly the bowed configuration accomplished provides thedesired lens for the photocell of the level control assembly.lmportantly. of course. it is essential that the lens configuration beuniform for successful operation of the photocell for each downfeed ofthe package tube.

Located generally beneath the level control assembly 18 and spacedconveniently along the length of the tubular member ll is the feedingassembly 19 previously alluded to. Fora better understanding of thisassembly, reference is particularly made to FIGS. 1 and 4. As thereinshown, a feeder block is slidably mounted on a vertical cylindrical post71 supported at its lower end on the lower arm portion 60 ofsupportbracket 61. The block member 70 is movable vertically up and down thepost 70 against the action of intervening spring means 72. Normally,spring means 72 serves to bias block 70 to its upper position asillustrated in FIG. I which is limited by an enlarged upper end portionof the post 70. An actuator link 73., responsively movable downwardlywith energization of a solenoid means 74, also supported on the outerend of the arm portion 60 on bracket means 6]. is connected to thefeeder block 70 as by a pivot pin.

With this described arrangement. it will be understood that energizationof solenoid means 74 serves to pull the block 70 downwardly against theaction of spring 72 with the latter returning the block 70 upwardly upondeenergization of the solenoid means 74. It further will be appreciatedthat the guide rod 71 is located to one side ofthe rod 58 which supportsthe liquid level assembly 18.

A second solenoid gripper means 76 is carried in a central opening 77 ofthe block member 75. The core of the solenoid means 76 is coupled to anactuator rod 78 which extends through an opening in an intermediate wallportion 79 of the block member 70 and is coaxially surrounded by aspring means 80. The outer end of actuator rod 78 is fixed to a movableL-shaped gripper member 8] whereby the latter moves responsibly with theactuator rod 78. In operation. cnergization of solenoid means 76 servesto move the gripper member 8| to the right as viewed in FIG. 4 or, thatis. toward block member 70 with the spring means 80 effecting returnmovement of the gripper member upon deenergization of the solenoid 76.

The gripper member St is slidably supported on the block member 70 bymeans of a connector pin or rivet 82 extending outwardly of one side 83of the block member 70 and through a slotted opening 84 (see FIG.

1) formed in a base arm 85 of the L-shaped gripper member 81. The otherarm 86 of the gripper member 81 extends at right angles to base arm 85thereof and is fixed. as previously described. to the outer end of theactuator rod 78. The outermost end of the arm 86 opposes a stationarygripper finger 90 formed at one adja cent corner of the block member 70.

In operation. when it is desired to downfeed the package tube 11. thesolenoid means 76 is energized. drawing the gripper member 86 inwardlytoward the stationary gripper finger 90 to pinch the adjacent margin 91of the package member 11 therebetween. Thereafter. solenoid means 74 isenergized, drawing the en tire block 70 downwardly against spring 72 tofeed the tubular member downwardly in accordance with the down-stroke ofthe solenoid-actuated link 73. .After completion of the down stroke. thegripper finger solenoid 76 is selectively decnergi7ed. releasing themargin of the tubular package member 1 1. following which solenoid means74 is deenergized. permitting return spring 72 to raise the feeder block70 to its uppermost position illustrated in FIG. 1.

In order to adjust the downfeed stroke of the assembly 19. block member71 is fitted with an adjustable stop bolt 92 at the innermost endthereof which may be adjustably positioned to engage the head of asecond adjustable stop 93 projecting upwardly from arm portion 60 ofbracket 61.

As previously mentioned. the package tube 11 having its bottom end 95sealed and the portion thereof below level 63 filled with liquid. isposition with its lower end gauge means 21 which is adjustably mountedon a sup port means 96. As shown best in FIG. 1. the gauge 21 comprisesa lower block portion 97 having a resilient spring finger 98 extendingupwardly from one side thereof. Finger 98 is disposed in spaced relationto the support 96 to provide a uniform spacing receptive of the lowerend of the package tube 11 and effectively determinative of the desiredthickness. Adjustable positioning of the gauge 21 is coordinated withthe downstroke of the feeder assembly 19 so that as successive packagesare sealed and cut from the lower end of the package tube 11 by means20. each down-stroke of the feeder assembly will reposition the lowersealed end of the tribe 11 in the gauge means. After the sealing andsevering operation by the means 20. the liquid-filled packages heldbetween the gauge 21 and support 96 may be removed by any comentionalknown means. unnecessary to describe herein.

The heat sealing and cutoff means 20 will be understood best from aninspection of FIGS. 1. -8 of the drawings. As particularly shown inFIG. 1. means comprises an actuating solenoid 100 having acoreresponsive actuator link 101 supported on an upwardly extendingbracket means 102. The lower end of the actuator link 101 is pivotallyjoined at 103 to one end of a l shaped rocker arm 104 comprising abottom cross arm portion 105 and a central stem portion 106. Pivotalconnection 103 is at one end of the cross arm 105 while the opposite endthereof is pivotally joined to a pivot block 107 by pin means 108. Aspring member 109 is coupled to and extends between the central stemportion 106 and the support bracket 102 to normally bias member 104 in aclockwise sense as viewed in FIG. 1. This action effects the return ofmember 104 to its upright position as illustrated in that figure upondeenergilation ofthe solenoid means 100. (onverselyg ener- Ill gizationof the solenoid serves to actuate the coreactuated link 101 upwardly.rocking member 104 counterclockwise about pivot pin 108 for purposes toappear presently.

At the upper end of the stem portion 106 is a transversely related.horizontal knife support arm 110. The right hand outer end of arm 110(see FIG, 1) is adapted to abut the upper end of bracket 102 to serve asa stop device for limiting clockwise movement of the '1'- shaped member104. as urged by spring means 109. Affixed to one upper side of arm 110.as by spot-welds 111 (see FIG. 8 is a generally rectangular shapedsealing plate member 112 having a sealing knife portion 113 extendingcentrally outward of one front marginal edge 114 thereof (see FIG. 8].The portion 113 is equipped with the usual heater wire 115 adjacent theouter tip end 116 thereof as best shown in FIG. 8.

Mounted on opposite sides of the sealing plate member 112 andintersecting substantially at right angles immediately in front oftheouter tip end 116 of portion 113 are a pair of planar wiper blademembers 118 and 1 19. each respectively associated with a pair ofsupport brackets 120. 120 and 121. 121 secured to opposite faces ofplate 112 as by rivet means 122. The connection between the wiper blades118 and 119 and their brackets 120. 121 is by pairs of leaf spring means125. 125. attached to the blades 118 and 119 and brackets 120. 121 byrivet means 126. It will be noted (FIG. 8) that such springs cross oneanother on opposite sides of knife portion 113.

It will he recognized from FIG. 1 of the drawings that the wiper blades118 and 119. with portion 113 disposed therebetween. is located on oneside of the package tube 11 directly opposite a stationary knifeassenthly comprising a bracket 131 affixed to a support. a stationaryheater blade 132 having heater wire 133 and a guard member 134 adjacentthe blade means 132. Specifically. the guard member 134 and blade 132are affixed to the support means 131 by mounting bolt 135. In operation.the movable blade 1 13 affixed to the upper end of the T-shaped member104 moves toward and away from the stationary blade 132. with theliquid-filled package tube 11 disposed therebetween.

It will be recalled that one of the principal problems confronted inpackaging liquids utilizing thermally sealed materials. such as plasticfilms. occurs when attempting to heat-seal the plastic films around theliquid at temperatures in excess of the normal boiling temperatures ofthe liquid being encapsulated. lt readily will be appreciated that ifboiling or gasifieation of the liquid does occur within the package.there is great risk and danger of violently disrupting the package andthis is even more so when. as in the present instance. it is intended tocompletely fill the package with liquid prior to sealing the same. Inpackaging liquids according to the present invention. it is preferredthat there be no partial gaseous atmosphere within a package of thepermeant liquids so that the effective area for permeation of the activeliquid ingredients through the walls of the plastic package can bemaintained at a predetermined constant. If the liquids should diffuseinto a gaseous atmosphere within the package interior. the gaseousmaterials will permeate through the walls of the package. at a lowerrate than the liquid and more importantly will reduce the area incontact with the liquid permeant. Consequently. if one is to maintain arate of permeation at a known constant. it is essential that either allliquid state or gaseous state permeation take place. but not acombination of both.

In order to hermetically seal a completely liquidfilled plastic packageutilizing heat sealing principles. particularly when packaging the morevolatile materials. the present invention presents a unique method andmeans for effectively isolating the liquid contents of the package fromthe zone of thermal sealing. To this end. particular reference is nowmade to FIGS. I. 5. 6 and 7 of the drawings.

As illustrated in these figures. the operational sequence for effectingthe desired heat sealing of the top margin of a packaged product filledwith liquid is set forth. As initially illustrated in FIG. I of thedrawings, the liquid-filled tube I I is in position ready for producinga thermal weld or seal across the top end of the selected bottom portionthereof to produce a liquid-filled packaged product [35 (see FIGS. 7 and9). This sealing operation is brought about by the means 20. theelements of which have been described hereinabovc.

As shown in FIG. 5. cnergization of the solenoid means I serves toadvance the scaling member H3 toward the liquid-filled package tube ll.Prior to engagement of the member 113 with the wall 14 of the tube I I.however. the wiper blades I18 and I I9 engage such wall well in advanceof the sealing tip end and serve to pinch wall I4 tightly against theopposing wall or film layer l4 and the secondary heater blade 132. Aswith the sealing blades 38 and 40 of assembly IS. the movable sealingmember I I3 is generally at an elevated temperature over that of thestationary blade 132 which for convenience sake herein may be termed hotand cold blades. respectively. Be that as it may. as shown in FIG. 5.initial contact and movement of the wiper blades I18 and H9 against thepackage tube II effectively pinches off the package tube between the twoopposing blades H3 and I32. Continued advancement of the hot blade I13toward the cold knife blade I32 causes the wiper blades H8 and 119 tomove laterally away from one another bowing the springs I25. 125'. asillustrated in FIG. 6. and thereby maintaining resilient pressurecontact with the plastic layer wall 14 of the tube. This effectivelywipes the liquid u 'nvardly and downwardly away from the zone of thermalsealing designated 136 in FIG. 6. In this state. the two layers l4 andI4 ofthc plastic tube are pressed firmly together and stretched acrossthe cold blade I32. with hack-up support therefor being provided by theadjacent platen ends of the support bracket 13] aml the shield memberI34 associated with and located laterally adjacent the cold blade I32.Continued advancing movement of the hot blade I32 brings the saute intocontact with the plastic walls of the tube member I I to produce athermal weld barrier laterally thereaeross. At eventual contact of bladeH3 with the cold blade I32. the tube II is severed and the bottomportion or tubular package I35. filled with liquid. is effectivelyseparated therefrom.

Deenergiration of solenoid means I00 causes returning movement of thehot blade I13 toward the right as viewed in FIG. 7 along with returningmovement of the wiper blades H8 and II). This frees the packaged productI35 for removal from the lower end ofthe tube member I I.

After the severing of the package 135 as hercinabove described. feederassembly l9 releases the tube 11 and then is actuated to downfeed thetube I I into the gauge means 2! thereby pulling the tube materialthrough the lateral margin sealing and trimming assembly [5. Inasmuch asthe liquid level within tube ll lowers with the downfeeding thereof. theliquid level control assembly l8 will sense. as heretofore explained.the absence of fluid within tube 1] opposite the photocell S6.Consequently, appropriate circuitry is energized to signal for theinflow ofliquid via the filler tube 13. Sufficient liquid is then addedto the tube I l to bring its level up to the desired static head controllevel 63 as previously explained.

From the foregoing description of the apparatus illustrated in FIGS. Ithrough 8 of the drawings and its operation. it will be readilyunderstood that the fundamental operating steps for the improvedprocedure for packaging liquids according to this invention has beenfully set forth. along with a preferred means for accomplishing thesame. Nevertheless. it is to be recognized that exact means of theapparatus described is not essential to the accomplishment of thedisclosed method and it is fully contemplated that various changes.modifications and substitutions can be made therein by those familiarwith the art without departing from the teachings ofthis invention. Forexample. instead of two separate tapes for the formation of the tubepackage I], the same may be produced from a single tape. folded overinto a double layer and then marginally scaled along one lateral edge.Additionally. the particular liquid supply system described is notnecessarily essential to the accomplishment of the described methodinasmuch as liquid may be supplied by any number of known systems.including pressurized control systems, gravity feed systems. pumps andso forth. Further. while the disclosed apparatus has basically beendescribed as being actuated by solenoid means. the functions thereof maybe accomplished by utilizing hydraulic. pneumatic. mechanical or othersystems well within the skill of the art. Of like import is the removalof the packaged items from the forming equipment which may be donemanually or by any number of known pick-off systems. Additionally. it isfully contemplated that the described photocell system for regulatingthe level of liquid within the tube It may be replaced by a variety ofother devices including pressure-sensitive switch means located to sensethe static head ofthc liquid in tube 11.

With respect to the packaged product I35 as herein described. it is notessential that the same be severed from the tube member II during thescaling operation of the means 20. To the contrary. it is fullycontemplated that it may. in certain instances. be desirable to presentan elongated product in which individual packets of liquid are separatedby intervening thermal-weld seals. but not individually severed ashereinabove set forth. It is also fully contemplated that differentpackage configurations and size may be employed. including the provisionof hanging tabs at one end of the scaled packets.

It also is to be noted. as best shown in FIG. 9. that the interiorsurfaces ofthe plastic layers 14 and 14', for the package are preferablyscored with a series of fine line scratches to provide a uniformcapillary distribution system over the interior walls of the package.This feature is of particular importance in distributing the liquidpermeants evenly over the interior of the package walls. especially whenthe package is in a near collapsed state. That is to say. as liquidpermeates through the package walls the volume of liquid thereindiminishes and the package walls gradually collapse inwardly underatmospheric pressure. When the liquid content is nearly exhausted, thecapillary feed system takes over to evenly distribute the liquid overthe entire interior surface area of the walls until all permeant hascscaped. In this manner, the effective area for permeation distributionof liquid through the package walls is maintained substantially uniformthroughout the package life. Without such a capillary distributionsystem or its equivalent. as the package walls collapse toward oneanother. areas appear where the opposing walls contact one anotherwithout any liquid therebetween. Such contacting areas are thenineffective to the distribution of permcant through the package walls.For similar reasons, bubbles of air or gases in the package are to beavoided, since such act to keep the walls separated and effectivelyprevent distribution of liquid over the interior wall surfaces,

I claim:

1. Apparatus for hermetically sealing, between op posing walls of athermoplastic package a gas-free body of liquid which is vaporizable atatmospheric conditions. said apparatus comprising means for forming avertically elongated tubular package blank sealed along the bottom andlateral margins thereof, means for filling said blank with the liquidbeing packaged, means for controlling said filling means to maintain apredetermined head of liquid in said blank to control package size,means for heat-sealing said blank within an area spaced from the bottommargin of said blank and located in a part of said blank filled withliquid, means for severing said blank within said area. and means foravoiding vaporization of the liquid during heat-sealing by displacingthe liquid in said blank from said area prior to heat-sealing and formaintaining the liquid in spaced relation from said area duringheat-sealing said means for avoiding liquid vaporization comprisingmeans for engaging the opposed surfaces of the Walls over a selectedregion which include said area and which extends above and below saidarea, and means for actuating said wall engaging means to press togetheropposing interior surfaces of said walls in said selected region withsufficient pressure so as to eliminate liquid thcrebetween, and tomaintain together the interior surfaces of said walls in said selectedregion during heat-sealing so as to retain the liquid being packaged inspaced relation to said area.

2. The apparatus of claim 1 wherein said wall engaging means comprises apair of wiper blade means engageable with one of said walls platen meansopposite said blade means engageable with the opposing wall, and meansfor moving said blade means apart in the direction ot'the length of saidpackage blank while main taining said walls pressed against said platenmeans thereby to wipe the liquid from the interior surfaces of saidwalls.

3. Apparatus according to claim 1 and further including gauge means forregulating the volume of liquid within the lower end of said blankbetween said bottom margin and said region.

1. Apparatus for hermetically sealing, between opposing walls of athermoplastic package, a gas-free body of liquid which is vaporizable atatmospheric conditions, said apparatus comprising means for forming avertically elongated tubular package blank sealed along the bottom andlateral margins thereof, means for filling said blank with the liquidbeing packaged, means for controlling said filling means to maintain apredetermined head of liquid in said blank to control package size,means for heatsealing said blank within an area spaced from the bottommargin of said blank and located in a part of said blank filled withliquid, means for severing said blank within said area, and means foravoiding vaporization of the liquid during heat-sealing by displacingthe liquid in said blank from said area prior to heatsealing and formaintaining the liquid in spaced relation from said area duringheat-sealing, said means for avoiding liquid vaporization comprisingmeans for engaging the opposed surfaces of the walls over a selectedregion which include said area and which extends above and below saidarea, and means for actuating said wall engaging means to press togetheropposing interior surfaces of said walls in said selected region withsufficient pressure so as to eliminate liquid therebetween, and tomaintain together the interior surfaces of said walls in said selectedregion during heat-sealing so as to retain the liquid being packaged inspaced relation to said area.
 2. The apparatus of claim 1 wherein saidwall engaging means comprises a pair of wiper blade means engageablewith one of said walls, platen means opposite said blade meansengageable with the opposing wall, and means for moving said blade meansapart in the direction of the length of said package blank whilemaintaining said walls pressed against said platen means thereby to wipethe liquid from the interior surfaces of said walls.
 3. Apparatusaccording to claim 1 and further including gauge means for regulatingthe volume of liquid within the lower end of said blank between saidbottom margin and said region.